Yep, I also managed to export in .psd, but the masks are just not as useful as I was hoping. I was probably over-expecting based on my first very positive impression of the software.

My hope was that the layered .psd file would look just like the finished stiched, with masks controlling the tansition between the images.

I probably need to test a bit more.

I did indeed not see any problems in the sky, but I saw some in grass in the foreground where the circular bottom edge of the images appeared a little bit. I had shot too close to the edge which is why this problem shows up. Had I taken a bit more clearance I could crop easily this small part.

I would say to first choose a focal range range based on your personal "vision" -- IOW how you "see" you landscapes.

When you stitch, you end up with a wider view, on average about 1/3 wider on a full-frame camera so a 50 shifted and stitched is about like a 32 or so.

IMPORTANT! Note that with smaller sensor, you effectively end up with an even wider FOV after the stitch. With 1.6x sensor cameras you can nearly double the frame for an effective FOV about 2x as wide as the primary lens. Now the same 50mm which is 80mm after the sensor crop factor, gets halved and now generates around a 40mm net effective FOV.

Make sense?

Also note that the aspect ratios and corresponding perspectives will differ depending on whether you stich the frames with the camera horizontally oriented as opposed to doing the same with the camera vertically oriented on the tripod.

FWIW, I use the 90TSE, Mamiya 50 and Oly 24 about equally on my full-frame 1Ds2 depending on the nature of my subject. With a 1.6x camera I would probably consider starting with something in the 24 to 50 range as 90 will be a bit long for most landscape images.

My favourite stitching program has always been Panavue's image Assembler. Whenever I've tried other stitching programs, they've either proved to be not as good, or if better, more cumbersome and definitely more time consuming (I'm thinking of expensive programs like the no longer available PowerStitch, or free programs like PTAssembler).

I'm trying to reduce the amount of time I spend sitting in front of a monitor, not increase it, so I have not tried PTAssembler. I have little doubt it can correct for perspective anomalies which IA might be unable to handle. However, for such situations I'll use my tilt & shift lenses, so for me, if I've chosen the right lens, there's not much that IA cannot successfully stitch.

Nevertheless, I was always disappointed that IA had a problem producing resulting files larger than 400MB (with Win98 it was only 250MB). There was also the problem of no 16 bit stitching.

Well, that's no longer a problem. Image Assembler version 3 comes in 3 flavours; Standard, Professional and Enterprise. The more expensive Professional and Enterprise editions stitch in 16 bit mode, support ICC profiles and image sizes up to 100,000 x 100,000 pixels.

If my maths is correct, that's 10,000 megapixels x 3 = 30 gigabyte files sizes in 8 bit and 60 gigabyte in 16 bit. This should be large enough for most purposes .

There are no doubt other refinements in version 3. Previous versions were a bit lacking in the precision of the fully automated stitching option. One could try it, with little time wasted, but more often than not the results were not flawless.

First impressions are, the new version has improved upon the precision of automatic blending. I just loaded into the program a mosaic of 4 images which were in numerical order. All I had to do was specifiy that the resulting image would consist of 2 rows and 2 columns before loading, then hit 'run' and stand back. Within a couple of minutes I had a perfect stitch.

This program is so good, if I owned a Mac I'd be tempted to sell it and buy a PC .

Jack, becuase I knew you used Realviz Stitcher, I gave it a try (albeit in demo mode). The seams were not so good, whereas those from PTAssembler in its Autocreate mode were undetectable to my novice eyes. This made me bite the bullet and begin on the Panorma Tools learning curve. For this, I have found John Houghton's tutorial Panaorma Tools - Using the Optimzer a rosetta stone.

Actually, I reduced them all to 4MB. The problem I'm having is that Autostitch doesn't seem to be able to deliver a 13 image stitch in a row. I have now succeeded by making 3x5 image stitches and then stitching the 3 groups of five. I've got a result that's very similar to what IA can produce and I'm therefore impressed considering this is a free program.

However, IA does appear to have significant advantages.

(1) Handles TIF and 16 bit images.

(2) Faster than Autostitch.

(3) Better capability to automatically pull a row of images in line despite the the fact the camera might not have been perfectly level, which results in a stepping effect with Autostitch and previous versions of IA.

(4) More seamless skies, which are very prone to revealing slight changes of hue. Autostitch is good but not quite as good as IA in this respect.

I'm sure there are some areas in which Autostitch excels. One that comes to mind is its ability to automatically recognise any image's position in the jigsaw. With Image Assembler, one has to specify the number of rows and columns and get the images in the right order.

As I mentioned before, each stitching program has its strengths and weaknesses. I'll experiment some more with Autostitch. If it can do something which IA can't, or at least do something more quickly, more accurately or more easily, then I'll use it.

The 'out of memory' message seems to be due to setting the system memory too high. 2Gb is worse than 1Gb

I converted the 16 bit 92MB images to 8 bit, reduced the file size to 4MB and saved in jpeg.

Yes, but file size has very little to do with how the image is represented in memory, as long as the image resolution is the same. You have to stop thinking of them as files. Think of them as e.g. 6000x4000 resolution images.

So if Autostitch doesn't do anything really clever, it probably loads all images into memory as 8-bit images at whatever resolution you're using.

Naively, a 22 Mpx RGB image in 8-bit mode takes 66 MB of memory, while in 16-bit, it takes 132 MB. Even if you compress the file to 2 bytes, it still has to expand it to a 22 Mpx image if it wants to keep everything in memory.

Then there is some additional memory overhead while it manipulates the images.

If we take your example with a 92 MB 16-bit TIFF RGB files, these would naively be 46 MB in 8-bit mode. 13 times 46 MB equals 598 MB, which is the bare minimum needed to keep just these images in memory without "cheating". If the program isn't cleverly written, it may actually keep not only the non-stitched images as well as the result in memory at the same time, but also the already-stitched image sources. So, at 6 images successfully stitched (276 MB) you would then possibly be using 276 + 598 = 874 MB of memory just on that.

Suffice it to say, I now carry the following as my main lenses for landscape photography:

Olympus 24 shiftOlympus 35 shiftMamiya 50mm shiftCanon 90 TSE

Jack, ever since your Digital Outback article I have been considering using your approach. Do you have a recommendation on a TS lens to start with for landscapes with on a Canon D10, given its smaller sensor size to your Canon 1Ds?

Would you mind elaborating a bit more on what you saw with the 3 lenses below on your 1DsMK2?

The 28 and 35 Nikkors perform very well within their range -- I would rank them on par or slightly above the Canon 45 TSE. Both fall off significantly at about 8~9mm shift on the horizontal, though in fairness to Nikon that is where they claim maximum shift is. You can get the full 11mm on vertical.

The Schneider/Leica 28 super angualon PC. I had high hopes for this lens, but was disappointed -- at least in the sample I tested. It was a very sharp lens un-shifted, but even just a few mm of shift and the image was degrading significantly. In the end, it was not really as usable as the 35 Nikkor and overall the 28 Nikkor offers significanly more shift. I will reiterate I only tested one sample of this lens so it could have been a bad copy and not indicative of this lens' performance in general.

Nikkor 85PC. This lens offers essentially the same performance as the Canon 90TSE. If you want the entire nit-pic, the Canon is barely sharper in the center, however the Nikkor stays consistent all the way to the corner and at the corner it shows barely sharper than the Canon. I called it a wash. If you already own the Nikkor, I'd say use it. OTOH, the Canon does AE and allows focus confirmation on Canon EOS cameras where the Nikkor does not.

Anybody else using Realviz stitcher? I find it does an incredible job, though is slow if you use the layered and masked psd output mode.

The tiff mode runs fast and leaves un-decetable seams about 90% of the time so I generally run it first. If I get an image with a visible seam, I then run it in psd mode so I can edit the blend masks myself.

Jack,By flat stitches, I take it you mean mosaics (or single rows) of 4, 8, 16 or 20 35mm images which end up looking like an ultra sharp 4x5 image (or 8x10 image) taken with a super lens impossible to build, rather than the whiz bang 360 degree QTVR panoramic effects.

That's what I'm interested in; exceeding the resolution limits of large format photography using small format cameras.

Image Assembler is very efficient at producing such images.

That's exactly what I mean by "flat." The only reason I stitich at all is to get more effective MP resolution for larger prints.

As an aside, this is the precise reason my main imaging lenses are shift lenses -- it is very easy to generate an almost perfect image overlap for later stitching, and by going flat, you have virtually none of the curved perspective distortions you get with sperical (panned or gimball-head) stitches or swing-lens cameras.

However, in some respects Autostitch is quite abysmal. There's no stitch so bad as no stitch at all. Despite setting system memory to the maximum 2GB in Autostitch's options and increasing pixel width and height, I frequently got 'out of memory' messages. I found it impossible to stitch 13 images in a single row, even after I'd reduced the image size from 16 bit 92MB tifs to 8 bit 4 MB jpegs.

If you think about it, it's hardly surprising. "JPEG" and "TIFF" only help you when you store things to disk. The images are still X times Y pixels, aren't they? By going from 16-bit TIFF-RGB to 8-bit whatever, you've only saved half the effective memory space. Depending on implementation, you may not even save that much.

Here you can see an article where I marked the L-bracket at 11mm intervals for use with the Canon TSE lenses under full shift -- scroll about half way through. The article explains in detail how to do the shift/counter-shift:http://www.outbackphoto.com/workflow/wf_58/essay.html

You start with the camera full right and the lens full left. Then move the lens right and camera left by 11mm and take shot two, 11mm more and take the last shot.